Biomineralized tetramethylpyrazine-loaded PCL/gelatin nanofibrous membrane promotes vascularization and bone regeneration of rat cranium defects

Conventional electrospinning produces nanofibers with smooth surfaces that limit biomineralization ability. To overcome this disadvantage, we fabricated a tetramethylpyrazine (TMP)-loaded matrix-mimicking biomineralization in PCL/Gelatin composite electrospun membranes with bubble-shaped nanofibrous structures. PCL/Gelatin membranes (PG), PCL/Gelatin membranes containing biomineralized hydroxyapatite (HA) (PGH), and PCL/Gelatin membranes containing biomineralized HA and loaded TMP (PGHT) were tested. In vitro results indicated that the bubble-shaped nanofibrous surface increased the surface roughness of the nanofibers and promoted mineralization. Furthermore, sustained-release TMP had an excellent drug release efficiency. Initially released vigorously, it reached stabilization at day 7, and the slow-release rate stabilized at 61.0 ± 1.8% at 28 days. All membranes revealed an intact cytoskeleton, cell viability, and superior adhesion and proliferation when stained with Ghost Pen Cyclic Peptide, CCK-8, cell adhesion, and EdU. In PGHT membranes, the osteogenic and vascularized gene expression of BMSCs and human vascular endothelial cells was significantly upregulated compared with that in other groups, indicating the PGHT membranes exhibited an effective vascularization role. Subsequently, the membranes were implanted in a rat cranium defect model for 4 and 8 weeks. Micro-CT and histological analysis results showed that the PGHT membranes had better bone regenerative patterns. Additionally, the levels of CD31 and VEGF significantly increased in the PGHT membrane compared with those in other membranes. Thus, PGHT membranes could accelerate the repair of cranium defects in vivo via HA and TMP synergistic effects.

MiR-183-5p promotes migration and invasion of prostate cancer by targeting TET1

BACKGROUND

Prostate cancer (PCa) is one of the common malignant tumors worldwide. MiR-183-5p has been reported involved in the initiation of human PCa, this study aimed to investigate whether miR-183-5p affects the development of prostate cancer.

METHODS

In this study, we analyzed the expression of miR-183-5p in PCa patients and its correlation with clinicopathological parameters based on TCGA data portal. CCK-8, migration assay and invasion and wound-healing assay were performed to detect proliferation, migration and invasion in PCa cells.

RESULTS

We found the expression of miR-183-5p was significantly increased in PCa tissues, and high expression of miR-183 was positively associated with poor prognosis of PCa patients. Over-expression of miR-183-5p promoted the migration, invasion capacities of PCa cells, whereas knockdown of miR-183-5p showed reversed function. Furthermore, luciferase reporter assay showed TET1 was identified as a direct target of miR-183-5p, which was negatively correlation with miR-183-5p expression level. Importantly, rescue experiments demonstrated TET1 over-expression could reverse miR-183-5p mimic induced-acceleration of PCa malignant progression.

CONCLUSION

Our results indicated that miR-183-5p could act as a tumor promoter in PCa and it accelerated the malignant progression of PCa by directly targeting and down-regulating TET1.

Effect of the Laying Order of Core Layer Materials on the Sound-Insulation Performance of High-Speed Train Carbody

The design of sound-insulation schemes requires the development of new materials and structures while also paying attention to their laying order. If the sound-insulation performance of the whole structure can be improved by simply changing the laying order of materials or structures, it will bring great advantages to the implementation of the scheme and cost control. This paper studies this problem. First, taking a simple sandwich composite plate as an example, a sound-insulation prediction model for composite structures was established. The influence of different material laying schemes on the overall sound-insulation characteristics was calculated and analyzed. Then, sound-insulation tests were conducted on different samples in the acoustic laboratory. The accuracy of the simulation model was verified through a comparative analysis of experimental results. Finally, based on the sound-insulation influence law of the sandwich panel core layer materials obtained from simulation analysis, the sound-insulation optimization design of the composite floor of a high-speed train was carried out. The results show that when the sound absorption material is concentrated in the middle, and the sound-insulation material is sandwiched from both sides of the laying scheme, it represents a better effect on medium-frequency sound-insulation performance. When this method is applied to the sound-insulation optimization of a high-speed train carbody, the sound-insulation performance of the middle and low-frequency band of 125-315 Hz can be improved by 1-3 dB, and the overall weighted sound reduction index can be improved by 0.9 dB without changing the type, thickness or weight of the core layer materials.

Experimental Study on Hydrate Safe Flow in Pipelines under a Swirl Flow System

With the development of oil and gas resources gradually extending to the deep sea, the blockage of gas hydrate is attracting more and more attention. How to inhibit hydrate blockage efficiently and economically in oil and gas gathering transportation pipelines and ensure the safe operation has become a hot and difficult point in the field of oil and gas gathering and transportation research. At present, the research on the safe flow of gas hydrate is still in the exploratory stage, and applying swirl flow to hydrate risk control technology has a great engineering application value. A systematic experimental study on the safe flow of gas hydrate in a swirl flow system is carried out herein. The experimental results show the following: (1) The laws of gas hydrate flow, transport, deposition, and pipe plugging under various experimental conditions of the swirl flow system are obtained, the safe flow region of hydrate under the swirl flow system in the pipeline is obtained, and the safe flow boundary of hydrate is expanded. (2) Beginning with the theoretical analysis of the safe flow of gas hydrate in a pipeline, the flow characteristics of gas hydrate in the flow system are described; the special flow form of swirl flow has a great influence on the safe flow law of hydrate. (3) The growth and coalescence mechanisms of spiral hydrate in two mainstream systems of separated flow and dispersed flow are explored and researched. The critical tangential velocity of flow is taken as the standard of criterion.

Numerical Simulation on the Flow Pattern of a Gas-Liquid Two-Phase Swirl Flow

The gas-liquid contact area can be increased by the gas-liquid swirl flow, and the heat and mass transfer efficiency between gas and liquid can be enhanced by the gas-liquid swirl flow. The gas hydrate formation can be promoted by the swirl flow. The swirl flow can ensure the safety of the natural gas hydrate slurry. The flow pattern and conversion law of gas-liquid swirl with a twist tape should be investigated, and numerical simulation has been carried out by using the Reynolds stress model and the level set model. As a result, four different flow patterns are obtained, namely, swirl-stratified flow, swirl bubble flow, swirl slug flow, and swirl annular flow. The influence of gas-liquid-phase velocity on the flow pattern is investigated. The drag force generated by the two-phase slip velocity can change the gas form. At the same time, the flow pattern at different positions of the pipe will also change because of the attenuation of the swirl flow. Finally, the flow pattern map of the gas-liquid swirl flow is accomplished, and it is compared with the Mandhane flow pattern map. The flow boundary of the swirl bubble flow and the swirl annular flow is predicted.

Efficacy of probiotic adjuvant therapy for irritable bowel syndrome in children: A systematic review and meta-analysis

Objective

Irritable bowel syndrome (IBS) affects children’s quality of life and learning. The purpose of this research was to systematically evaluate the efficacy of probiotic adjuvant therapy for IBS in children.

Methods

The Web of Science, PubMed, Cochrane Library, EMBASE and Clinical Trials databases were electronically searched for randomized controlled trials (RCTs) published prior to January 2021 exploring the use of probiotic adjuvant therapy for IBS in children. Strict screening and quality evaluations of the eligible articles were performed independently by 2 researchers. Outcome indexes were extracted, and a meta-analysis of the data was performed using RevMan 5.4.1 and STATA 16 software. Finally, the risk of bias in the included studies was assessed with the RCT bias risk assessment tool recommended in the Cochrane Handbook for Systematic Reviews of Interventions (5.1.0).

Results

A total of nine RCTs were included. In children, probiotics significantly reduced the abdominal pain score (I² = 95%, SMD = -1.15, 95% (-2.05, -0.24), P = 0.01) and Subject’s Global Assessment of Relief (SGARC) score (I² = 95%, MD = -3.84, 95% (-6.49, -1.20), P = 0.004), increased the rate of abdominal pain treatment success (I² = 0%, RR = 3.44, 95% (1.73, 6.87), P = 0.0005) and abdominal pain relief (I² = 40%, RR = 1.48, 95% (0.96, 2.28), P = 0.08), and reduced the frequency of abdominal pain (I² = 2%, MD = -0.82, 95% (-1.57, -0.07), P = 0.03). However, we found that it might not be possible to relieve abdominal pain by increasing the daily intake of probiotics.

Conclusions

Probiotics are effective at treating abdominal pain caused by IBS in children, however, there was no significant correlation between abdominal pain and the amount of probiotics ingested. More attention should be given to IBS in children, and a standardized evaluation should be adopted.